How cheap do you want? You do not want to skimp on a PSU, do you want to have to re buy your whole PC in 6 months time because you didn't want to pay a few £'s more?
You could think of it like this the Americans pay $120 for the Hiper, the same as a modstream 520w so it is a bargain.
Yeah it will be fine assuming you are not having loads of hdd.
I have a Antec 450w smartpower in the PC next to me with a 6600gt and a opty CAB2E 05 (not my PC.) and it is barely making a sweat over it, as the rear PSU fan only goes on with high load and it has barely gone on.